244 NOTES AND COMMENTS [ocroBER 
“localisation” of developmental processes which appears to the author 
to bring out clearly the distinctive character of an organism as opposed 
to an inanimate system. The first illustration given may make the 
matter plainer. 
Some four years ago Driesch showed that if a fully-formed 
gastrula of a sea-urchin (Sphaerechinus granularis) be halved equa- 
torially, so that each half has half of the ectoderm and half of the 
archenteron, both portions heal up and become spherical again, and 
both soon show a gut divided in the normal proportions into three 
parts. This is a simple instance of a familiar kind of phenomenon 
which appears to the author to prove the necessity of vitalistic inter- 
pretation. No chemico-physical interpretation will suffice. 
We cannot here summarise the author’s argument, not that it is 
particularly difficult—for Driesch’s style is limpid compared with that 
of many—but because of the difficulty of translating the terminology. 
It may be all right in German and in Germany, but we doubt if the 
conversion of English biologists is likely to be attained by discussions 
on “Der primir-regulatorische Charakter der Differenzirung har- 
monisch-aquipotentieller Systeme,’ and the like. The little book was 
written in about two months; it seems to us that in this, and even 
more in other cases, it would have been well if the author had spent 
an equal amount of time in making the wisdom of his counsel more 
generally available to busy biologists. 
To return for a moment to the subject-matter. The machine 
theory of an organism is insufficient, since some of the most char- 
acteristic vital phenomena seem to transcend the categories of 
mechanism. And even if we come to understand a living creature as 
we understand a steam-engine, there remains the idea behind them 
both. Sooner or later we have to fall back upon an unknown 
“ Gesetzlichkeit.” The author’s contention is that there is in the 
organism an elementary irreducible “ Gesetzlichkeit.” To overlook 
this, he says, is hke overlooking the spider in our science of the web. 

Morphology of the Sting in Hymenoptera. 
THE embryological researches of the last twenty years seem to have 
securely established that the stinging apparatus in ants, bees, and 
wasps is derived in part from ventral segmental outgrowths, and in 
part from the integumentary skeleton of certain segments. In a 
recent paper (Zettschr. wiss. Zool. lxvi. 1899, pp. 289-333, 2 pls.) 
Dr. Enoch Zander has analysed the apparatus in a number of repre- 
sentative forms, and has shown in detail how much of it is referable 
to (the 11th and 12th) segments of the abdominal skeleton, and how 
much to the genital appendages or gonapophyses. He shows further 
